Evidence for triplet superconductivity near an antiferromagnetic instability in CrAs

ORAL

Abstract

Unconventional superconductivity, where the Cooper pairs are bound by a mechanism other than the conventional electron-phonon pairing mechanism described by BCS theory, has often been found to occur in close proximity to magnetic order in systems such as the cuprates, iron pnictides and heavy fermion superconductors. Recently CrAs has been discovered to show superconductivity as the helimagnetic order is suppressed by applying pressure[1], suggesting possible unconventional superconductivity. To reveal the nature of the superconducting order parameter of CrAs, we performed measurements of the angular dependence of upper critical field(Bc2) of CrAs under pressure using a triple-axis vector magnet. We find a clear anisotropy of Bc2 in the bc plane, where both two-fold and six-fold oscillatory components are observed, which are consistent with an unconventional odd-parity triplet superconducting state[2].

[1] W. Wu et al., Nat. Commun. 5, 5508 (2014).
[2] C. Y. Guo et al., arXiv: 1710. 06707 (2017).

*This work was supported by the National Key R&D Program of China and the NSFC.

Presenters

  • Chunyu Guo

    • Zhejiang University, Center for Correlated Matter and Department of Physics
    • Center for Correlated Matter and Department of Physics, Zhejiang University

Authors

  • Chunyu Guo

    • Zhejiang University, Center for Correlated Matter and Department of Physics
    • Center for Correlated Matter and Department of Physics, Zhejiang University
  • Michael Smidman

    • Zhejiang University, Center for Correlated Matter and Department of Physics
    • Center for Correlated Matter and Department of Physics, Zhejiang University
  • Wei Wu

    • Chinese Academy of Scienes (CAS)
  • Jiangping Hu

    • Institute of Physics,Chinese Academy of Sciences
    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Scienes (CAS)
    • Institute of Physics, Chinese Academy of Scienes (CAS)
  • Jianlin Luo

    • Chinese Academy of Scienes (CAS)
    • Chinese Academy of Sciences
  • Huiqiu Yuan

    • Zhejiang University, Center for Correlated Matter and Department of Physics
    • Center for Correlated Matter and Department of Physics, Zhejiang University
    • Zhejiang University